Long spin relaxation times in wafer scale epitaxial graphene on SiC(0001)

TL;DR

This paper reports the development of a scalable process for creating spin-valve devices on epitaxial graphene on SiC(0001), revealing exceptionally long spin relaxation times but reduced diffusion coefficients, with implications for spintronics.

Contribution

It introduces a scalable fabrication method for epitaxial graphene spin devices and provides new insights into spin relaxation properties on SiC substrates.

Findings

Longest spin relaxation times observed in epitaxial graphene

Reduced spin diffusion coefficient compared to exfoliated graphene

Possible substrate influence on spin relaxation times

Abstract

We developed an easy, upscalable process to prepare lateral spin-valve devices on epitaxially grown monolayer graphene on SiC(0001) and perform nonlocal spin transport measurements. We observe the longest spin relaxation times tau_S in monolayer graphene, while the spin diffusion coefficient D_S is strongly reduced compared to typical results on exfoliated graphene. The increase of tau_S is probably related to the changed substrate, while the cause for the small value of D_S remains an open question.